Lock.



PATENTED MAR. 17, 1908.

E. EIGHLER.

LOCK. APPLIOATION FILED JULY 18, 1907.

THE NORRIS prrzks co., WASHINGTON, D. c.

UNITED sTArns PATENT OFFICE.

ERNST EIOHLER, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO AMERICAN ELEC-TRIO ALARM COMPANY, OF PITTSBURG, PENNSYLVANIA, A CORPORATION OF NEWJERSEY.

LOCK.

T 0 all whom it may concern:

Be it known that I, ERNST EIOI-ILER, a citizen of the United States ofAmerica, residing at Pittsburg, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements inLocks, of which the following is a specification, reference being hadtherein to the accompanying drawing.

This invention relates to locks, and the invention relates moreparticularly to looks for doors of fire alarm and patrol boxes,especially the former.

The invention has for its object to dispense with the use of tumblersand similar pivoted members, commonly employed in a lock for operatingthe lock bolt thereof, and prevent the look from being picked orsurreptitiously unlocked.

My invention aims to provide a novel trap for looking a key in the doorof a fire alarm box, after the door has been opened. It is a well knownfact that considerable trouble has been experienced with traps anddevices heretofore used, necessitating the breaking of doors and keysand even the locking mechanism in order to remove the keys from thedoors. My invention obviates the above trouble by providing positivemeans for releasing a key, said means being arranged to be easilymanipulated by an auxiliary key, after the door of a box has beenopened. To this end I use simple and inexpensive parts easily arrangedwithin a lock casing, the principal part of my invention constituting atrap, for holding the bolt of a lock in an unlocked position, until thetrap is released by an auxiliary key. In connection with the trap amovable spring held slide is used, which is moved prior to the lockingbolt, whereby the locking bolt will be placed in condition to receivethe trap, and prevent either said trap or locking bolt being moved orthe key removed from the lock casing, until the auxiliary key isinserted in the lock casing from the inner side of the door of a box.

The detail construction of my lock will be presently described and thenspecifically pointed out in the appended claims.

In the drawings, Figure 1 is a plan of the look, illustrating thelocking bolt thereon in a position which it would assume when holding abox door in a closed position, Fig. 2 is a simi- Specification ofLetters Patent.

Application filed July 18, 1907.

Patented March 17, 1908.

Serial No. 384,463.

lar view illustrating the locking bolt withdrawn and the trap as holdingsaid bolt, Fig. 3 is a cross sectional view of the lock, illustrating alock plate in position, Fig. 4 is a perspective view of the slide usedin connection with the lock, Fig. 5 is a detail sectional view of thelock, illustrating the main key opening thereof, together with a part ofthe key, and F ig. 6 is a plan of a lock with the bolt thereon withdrawnand the trap door about to release said bolt.

To put my invention into practice, I provide a rectangular or othersuitably shaped casing 1, having a plurality of pierced proj ecting lugs2 by which the lock casing is secured to the inner side of the door (notshown) of a fire alarm or patrol box. The casing 1 is provided with aplurality of posts 3 having threaded openings 4 for receiving screws 5employed for holding a back plate 6 in the lock casing 1, the outer sideof said back plate lying flush with said casing.

In the lock casing is slidably mounted a bolt 7, having a beveled end 8extending into an opening 9 formed in the end of the casing 1. Theopening 9 serves as a guide for the protruding end of the bolt, while apost 10, washer 11 and a screw 12 serve to guide the opposite end of thebolt 7, said post being carried by the casing 1 and extending through anelongated opening or slot 1 1 provided therefor near the inner end ofthe bolt.7.

The beveled end S of the locking bolt 7 is made of a greater thicknessthan the remainer of the bolt, thereby providing a shoulder 15, which isrecessed as at 16, to receive the end of a spring 17, wound around apost 18 carried by the lock casing, the other end of said spring bearingagainst the top wall 19 of the lock casing 1. A washer 20 and a screw 21are employed for retaining the wound portion of the spring 17 around thepost 1.8. The tension of the spring is exerted to normally hold thebeveled end 8 of the locking bolt in an extended or looking position.

The look bolt 7 has its lower edge cut away, as at 22, providing avertical shoulder 23, and is also provided with a notch 24 for thereception of a vertically disposed trap pin 25, said pin being guided bythe lower wall 26 of the lock casing and a block 27 secured in saidcasing by screws or similar fasinserted in the lock casing.

tening means 28. The trap pin 25 is pro-' vided with a collar 29 andinterposed between said collar and the lower wall 26 of the lock casingis a coil spring 30, said spring surrounding the trap pin and normallyexerting a tension sufficient to elevate said trap pin, when released.

The trap pin is normally held out of engagement with the lock bolt 7 bya metallic inverted channel-shaped slide 31., said slide being formedwith an elongated opening 32 for a post 33, said post being providedwith carried by the forward end of the slide 31.

The slide plate is provided with laterallyextending flanges on itslongitudinal edges, and one of these flanges is provided with anextension 41 normally closing the lower edge of the notch 24 andpreventing the spring pressed trap pin 25 from entering said notch orcontacting with the bolt 7, until the slide 31 is moved and the lockbolt 7 drawn inwardly into the lock casing.

The plate 6 is provided with a key hole 42 alining with an opening 43formed in the opposite side of a lock casing. These openings aresurrounded within the lock casing by sleeves 44 constituting means forpreventing keys, other than the proper ones, from being I haveillustrated a key 45 having a bit 46 as placed in the lock casing (seeFig. 5). The lower wall 26 of the lock casing is provided with anopening 47 allowing dirt, carried into the lock casing by a key to passfrom said lock casing. The casing is also provided with a key hole 48directly beneath the lock bolt and at one side of the block 27, this keyhole accommodating a release key employed for manipulating the trap pin25.

The operation of the lock is as follows: Assuming the door of a firealarm box is held in a closed position by the beveled end 8 of the lockbolt 7, and it is desired to open the door, the key 45 is inserted inthe lock casing and turned to the left, until the edge of the bit 46impinges the lug 37 of the slide 31. A

further movement of the key 45 moves the slide 31 until the lug 37engages the shoulder 23 of the lock bolt. This movement of the slide 31places the spring 38 under tension and moves the extension 41 frombeneath the notch 24 of the lock bolt 7. A still further movement of thekey 45 moves the lock bolt 7 inwardly, until the extension 41 releasesthe trap pin 25, at which time, said pin is moved upwardly into thenotch 24 of the lock bolt, this being accomplished by the coil spring'30 which has been normally held under tension. The upward movement ofthe trap pin 25 is limited by the collar 29 engaging the block 27. Theinward movement of the lock bolt 7 has placed the spring 17 undertension, whereby when said lock bolt is released, said spring will movethe lock bolt to its normal position shown in Fig. 1 of the drawings.Since the trap pin 25 holds the lock bolt in a withdrawn position, itwill be impossible to remove the key 45 from the lock casing so long asthe lock bolt 7 is withdrawn. This is due to the fact that the cut awayedge 36 of the slide 31 prevents a rearward movement of the key bit 46and it is impossible to force the slide or bolt outwardly on account ofthe trap pin 25. As soon as the door has been opened, the release key(not shown) can be inserted in the key hole 48 and rotated to engage thecollar 29, and lower said collar and the trap pin 25. Immediately uponthe trap pin passing out of the notch 24 and releasing the extension 41,

which is frictionally held in engagement with said trap pin by thespring 38, the spring 17 returns the lock bolt 7 to its normal position,while the spring 38 returns the slide 31 to its normal position. Themovement of these two elements permits of the key 45 being removed fromthe lock casing, and after the release key has been removed from the keyhole 48, the door of the box can be closed. Since the lock bolt 7 isheld by a spring, a door equipped with the lock can be closed and heldin a locked position without the use of a key. It will therefore beapparent that I have devised a spring lock having a novel trap forlocking a bolt in a withdrawn position and retaining the bolt actuatingkey in the lock casing.

The key for insertion in the keyhole 48 which key has not been shown,and has been herein termed as the release key is often known as anofiicers key, while the key 45 is generally known as a "citizens key. Asit is often desirable that an officer, or other authorized person mayobtain access to a fire alarm box without trapping his key therein, itis my usual practice in constructing the locks to form the lug 37shorter than the width of the shoulder 23 on the lock bolt, so that theofhcers or release key can be inserted in key-hole 42, and as the bitthereof is so shaped that it will clear or miss the lug 37, the lockbolt alone is thrown back or withdrawn, whereas when a citizens key isinserted the bit thereof will engage the lug 37 and thus draw back boththe slide 31 and the bolt 7, and trap such key.

The simplicity of construction entering into my invention not onlyprovides an inexpensive lock, but insures positive action of the same,and thereby reduces the expense of maintenance in connection with themany locks used upon fire alarm and patrol boxes.

Having fully described my invention, what I claim and desire to secureby Letters Patent, is

1. A look consisting of a casing having openings formed therein, aspring pressed movable lock bolt arranged in said casing and normallyextending into one .of said openings, said lock bolt having its loweredge cut away providing a notch and a shoulder, a movable spring heldslide mounted upon said bolt, said slide being cut away to provide a luglying normally parallel with said shoulder, an extension carried by saidslide for normally closing the lower end of said notch, a spring pressedtrap pin slidably mounted in said casing for engaging in said notchandholding said bolt in a withdrawn position, a key adapted to be insertedin said casing for first moving said slide and then said bolt, and meansfor lowering said trap pin and releasing said bolt and said slide.

2. In a look, a lock casing, a lock bolt slidable therein having ashoulder and also provided with a notch,a plate mounted on the lock bolthaving an extension normally projecting over the notch in the bolt andsaid plate having a lug to engage the shoulder on the lock bolt wherebywhen engaged by a key the lock bolt is withdrawn and the slide is movedto uncover the notch in the bolt, means for engagement with the notch ofthe bolt to hold the latter in withdrawn position and in the path ofwithdrawal of said key, and means whereby the first mentioned means isreleased to permit of the return of the lock bolt to its normalposition.

3. A look embodying a casing, a spring held lock bolt movably mountedtherein, and normally protruding from said casing, said bolt having anotch formed therein, a spring held slide movably mounted upon saidbolt, an extension carried by said slide for normally closing the lowerend of said notch, a spring pressed trap pin engaging said slide andadapted to enter the notch of said bolt, means for moving said slide andsimultaneously moving said lock bolt, and releasing said spring pressedpin, and means for moving said spring pressed pin and releasing saidslide and lock bolt.

4. In a spring lock, the combination with a casing, and a key, ofaspring pressed lock bolt movably mounted in said casing and normallyprojecting therefrom, a spring pressed slide movably mounted upon saidbolt, a spring pressed trap pin movably mounted in said casing forengaging said lock bolt and holding the same in a withdrawn position,means permitting of said key first moving said slide and then said bolt,

' and means for moving said spring pressed pin, and releasing said slideand lock bolt.

5. In a spring lock, the combination with a easing, of a spring pressedlock bolt mounted in said casing and projecting there from, a springpressed slide mounted upon said bolt, and cutaway to permit of a keymoving said slide and said bolt, means located in said casing forengaging said bolt to hold same withdrawn and in position to preventwithdrawal of the actuating key, and means for releasing the firstmentioned means and allowing said slide and bolt to assume their normalposition.

6. A lock comprising a casing, a spring pressed lock bolt arrangedtherein, a spring pressed trap pin for engaging said bolt and holdingthe same withdrawn and in position to prevent withdrawal of theactuating key, means for normally holding said pin out of engagementwith said bolt, means for releasing said pin, and means for returningsaid bolt to its normal position.

7. A lock comprising a casing, a spring pressed bolt arranged therein, atrap pin for engaging said bolt and holding the same in a withdrawnposition, means for normally holding said pin out of engagement withsaid bolt, means for releasing the first mentioned means, and means forreleasing said pin and allowing the first mentioned means and said boltto assume their normal position.

8. In a lock, the combination with a spring-pressed lock bolt cut awayin one of its longitudinal edges to form a shoulder, of a slide platemounted for movement on the lock bolt cut away in one longitudinal edgeto conform to the cut away portion of the lock bolt and having aninwardly-extending lug projection over the shoulder of said lock bolt,the said slide plate being movable on the lock bolt independently of thelatter when actuated until the lug thereof engages the shoulder on thelock bolt and movable in unison with the lock bolt after suchengagement, an extension carried by the slide plate normally projectingover a notch formed in the lock bolt, and means acting automaticallywhen the bolt and slide plate are retracted and the said extensionwithdrawn from over the notch in the lock bolt to engage in said notchand lock the bolt and slide plate in retracted position, the said meansremaining inactive when the lock bolt alone is retracted.

9. In a look, a spring-pressed lock bolt cut away in one of itslongitudinal edges to form a shoulder, a spring-held plate mounted formovement on the lock bolt cut away in one longitudinal edge to conformto the cut away portion of the lock bolt and having a lug lying parallelwith the shoulder of said lock bolt, said spring-held plate beingmovable on the lock bolt independently of the latter until the lug ofsaid plate engages the shoulder of the lock bolt and movable in unisontherewith after such engagement, and means acting automatically When thelock bolt is Withdrawn to secure the same, the said lock bolt and platein Withdrawn position acting to prevent the Withdrawal of theactuating-key.

In testimony whereof I afiix my signature in the presence of twoWitnesses.

ERNST EICHLER.

W itnesses FRED DANNENFELS, MAX H. SROLOVITZ.

